Apparatus for treating material in a vacuum



Aug. 10 1926.

O. MINTON APPARATUS FOR TREATING MATERIAL IN A VACUUM Original Filed March 4, 1920 2 Sheets-Sheet l Patented Aug. 1o, 1926.

,UNiT-l-:D STATES 1,595,488 PATENT OFFICE.

OGDENMINTON, oF GnnnNwIcH. coNNnc'rIcU'r.

/Arranarus Foa mammina MATERIAL 1N a vacuum.

Original application led lai-ch 4, 1920, Serial No. 363,349. Divided and this application died Iarch 2o, 1922, serial No. 545,214..

This application is a' division of my co- 'iending application, Method of treating naterial in a'vacuum and apparatus, iled March 4, 1920, Ser. No. 363,349, Case E.

The presentinvention relates to an apparatus and method for coating or coloring, or sizing or impregnating paper or other sheet. material, in a vacuum chamber, and drying said sheet material in the vacuum chamber before it is again subjected to-the atmosphere. y

My improved method consists in passing the sheet material which .is to be coated, colored, sized or impregnated into avacuum chamber through a liquid sealing medium which has no ailinity for the material, then coating, coloring, sizing or impregnating the paper or other sheet material while in the vacuum chamber, then drying the coated, colored, sized, or impregnated sheet material while still in the vacuum chamber, and then passing the dried material out of the vacuum chamber through a seal.

My -method may be practiced by the use of various forms of apparatus, dierent forms being illustrated by way yof example.

My invention further relates to obtaining a better and more uniform product than any now known on the market. My invention further relates to the method of coating or .impregnating sheet material which insures that there w1ll be no blemishes uneven surfaces, blisters or minute raised portions due to the airA which may be held or occluded Within the sheet material which, in the present practice of coating as for example with a water-proof compound, leads to rejections or discards due to these imperfections with the consequentl waste of material and labor.

' substantially impairing the coloring matterv and mordants used in' the paper. Among other advantages this insures that the paper Renewed February 17, 1928.

will have bri ht colors, which will `be substantially uni orm in diiierent runs of paper,

permitting matching of colored paper without any appreciable difference in tone or color.

My invention further' relates to rapidly and expeditiously coating or impregnating sheet material in a continuous web or sheet.

My invention further relates to sizing paper in a vacuum chamber and drying the sized paper in said vacuum chamber at such low temperatures as not to in'ure the fibers of the paper or the size. My 1nvention fur-v ther relates to withdrawing the occluded air from the paper and immediately fillin the interstices normally filled with the occ uded air with the size, and then drying the thoroughly sized paper in the vacuum chamber before it-"is subjected' to atmospheric conditions. My invention further relates to carrying out this 4method continuously with a continuous web of paper whichpasses into and out of the vacuum chamber without breaking the vacuum.`

My invention further relates to certain steps, and combinations of steps, also to certain elements and combinations of elements, whereby the method or processes hereinv described may be carried out, as well as t0 certain details of construction, all of which will be more fully hereinafter described in the specification and pointed out in the claims.

The accompanying drawings,-which are partly diagrammatic, illustrate slightly different forms of apparatus, but of course not the only ones, by which my improvedmethod may be practiced. s

Fig. lis a vertical diagrammatic section in which a heated bath is` used to dry the material;

Fig. 2 is a vertical diagrammatic section in which a heated bath and drums or cylinders are used to dry and finish the ma-V tinctly understood that textile fabrics may also be treated by my process and that my claims cover all forms of sheet materials.

In the ordinary drying of a web of aper such high heat is used as to injurious y affect the fibers of the paper; and in case the paper is colored it will materially affect the coloring matter and mordants used. Drying paper in the high temperatures used in ordinary practice often affects the size so that the resulting paper varies in quality, is not uniform and is not a perfect product.

In coating or impregnating fabrics it is found in practice that the coated fabric will frequently have blemishes due to large or small blisters and blow holes, these often being about the size of a pin-head or a pin-point. This is caused by the air which is held or occluded being collected, more or less, in small pockets under the coating or impregnating material, or in some cases'l causing minute blow holes. In waterproof fabrics this results in large quantities of the material being rejected with the consequent loss to the manufacturer.

y my invention I insure that substantially all the occluded air is withdrawn from the sheet material which will permit the coating or impregnating material, whatever it may be, to thoroughly iill these minute interstices or pockets normally occupied by occluded air, forming thereby a better and more uniform product and one devoid of blisters, blow holes or such blemishes. By my invention I immediately dry such coated or impregnated sheet material while still in the vacuum chamber so that when ,the sheet material emerges from the vacuum chamber the coating or impregnating materia-l is dry and set without any danger of atmospheric pressure or atmospheric conditions spoiling or marring the 'finished product.

As previously stated I will describe my invention with relation to coating, coloring or impregnating paper, though it is to be understood that textile fabrics may be treated in the same manner.

The web 1 of paper is fed from the reel or roll 2 over the guide roll 3 into a liquid seal 4. The liquid of this seal may be of any suitable material which has no aiinity for, or deleterious action upon, either the web 1 as it is first fed into the machine or after it has been coated or impregnated. I preferably employ mercury a-s the sealing medium 4, but it is to be distinctly understood that any amalgam, alloy, or any other suitable liquid sealing medium may be employed which has the characteristics above specified.

I have shown my invention in Fig. 1, in which the web 1, after passing through the liquid seal 4 over the guide roller 6 and through the coating or impregnating bath 7 passes into a vacuum chamber A, over a guide roller l() and is fed through a heated liquid bath 11. This bath may be of any suitable material which has no affinityfor or deleterious action upon the web 1. Preferably it is heated mercury, but it is to be distinctly understood that it may be an amalgam, alloy, or any other suitable medium which has the characteristics above specified. Preferably this heating bath 11 is heated by the steam pipes 12, 12. Preferably, though not necessarily, the web 1, after being coated or impregnated, is fed through the heating bath 11 by passing under one or more submerging rollers 13, 13 and over guide rollers 14, 14. The web then passes over the guide roller 15 and out through the second liquid seal 4, under the submerging roller 16 and over the guide roller 17 where it is preferably immediately wound into the finished roll or reel 18. y

In some cases it may be desirable to give -the coated or impregnated web 1 a finish and smoothness different from what it is given in the apparatus shown in Fig. 1. I may for example pass the web 1, Fig. 2, into a vacuum chamber A through a liquid heating bath 11 of any suitable medium which has no atlinity for or deleterious action upon the web 1, as, for example, mercury, amalgam, an alloy or any other suitab-leli uid having the characteristics above speci ed. In passing the web 1 through this heating bath 11 I employ drums or cylinders 20, 20 which may be heated or not and which are partially submerged in the bath 11. These drums may be rotated in any suitable manner.

The web 1 passes in Contact with these drums 20 and also with the guide rollers 25, 25 until it reaches the end of the vacuum chamber A at which point it is thoroughly dried and the coating or impregnating material thoroughly set. The web is then wound into the roll 18, after passing out of the second seal 4.

The liquid bath 11 may be heated in any suitable manner such as by passing steam, or products of combustion through the chamber 26.

The linish. of the web may be still further varied by 'changing the size of the rollers 20, 20. These changes may be in wide limits. Simply for purposes of illustration I have shown another variation in which the vacuum chamber A, Fig. 3, is provided with the same liquid bath 11 and guide rollers 25, 25, but with smaller drums or cylinders 27, 27. In this modification the web will not have a finish quite so flat and smooth as given by the apparatus in Fig. 2, but will give a flatter and smoother finish than given by the apparatus of Fig. 1. While these different forms are shown it is of course to be understood that they are simply illustrative and that my invention is not to be confined to them.

The vacuum chambers A are provided with pipes 2l, 21 leading to any suitable vacuum apparatus to maintain a vacuum in the vacuum chamber. I also provide the chamber with windows 22, 22 so that the interior can be seen by the operator.

By my process and apparatus the web of sheet material, whether it be paper or textile material, is rapidly coated or impregnated and immediately dried within the vacuum chamber so that when it emerges the coating or impregnating material is dried and set permitting it to be vimmediately wound into a roll or reel for transportation.

The thermal efficiency of my vacuum method is very much greater than thatl of the atmospheric cylinder drying heretofore in universal use of drying paper. Theoretically, it requires about 5,287 pounds of steam to dry one ton of paper at atmospheric pressure, but to compensate for convection and conduction losses, and those due to leaks in the piping system, and other inefficiencies, it has been shown in practice that about 10,600 pounds are required.

In my method, using a vacuum of about 28 the convection, conduction and piping losses are exceedingly small and the total steam required to dry a ton of paper by my method is approximately 5,200 pounds.

It is an established fact that paper dried at low temperatures is much stronger than l when it is dried at the high temperatures used in paper machine atmospheric drying. Paper dried in a vacuum of 28, or at a temperature of about 100o F., as in my method, is very much stronger than paper dried at atmospheric pressure, when the steam in the driers is at 228 F. When paper is dried by my method, therefore, a cheaper furnish can be used and still produce a coated or sized paper equal in strength to atmospheric dried paper, in which a higher grade furnish is used. In making newsprint paper, I am able to dispense with a considerable portion of the more expensive sulphite pulp, as this can be replaced with the cheaper ground wood pulp. By my method I also reduce the number of breaks in the web as it passes over the cylinder.

Furthermore, in my method there is a great'saving of heat (or steam) because the process is carried on in a vacuum chamber which acts on the principle of a thermos bottle, and the steam and vapors driven out of the wet paper are caught in the closed vacuum chamber, and conducted away to' the condenser. The operating room is free from steam, humidity and heat, and fans, and exhausters are dispensed with. In the use of my method the apparatus is at all times operating under delinite humidity, the control of the drying can be closely standardized and the moisture content in the paper carefully regulated. y

I am enabled also to use a comparatively small machine, which takes up comparatively small floor space thereby reducing overhead expenses. Having pointed out the many advantages of my method and apparatus over those heretot'ore used, it will be apparent that the use ofmy inventionresults in great economy in the initial cost of apparatus and in large savings in cost of operation, maintenance and repairs.

Having thus described this invention in connection with illustrative embodiments thereof, to the details of which I do not desire to be limited, what is claimed as new and what is desired to secure by Letters Patent is set forth in the appended claims.

1. An apparatus for treating material including a vacuum chamber, means to permit material to pass into and out of Said vacuum chamber without breaking the vacuum, coating or impregnating means mounted in the vacuumchamber, and combined drying drums or cylinders and a li uid bath cooperating to dry the material, the dryin drums or cylinders mounted in the liqui and adapted to give a smooth finish to the material to be dried.

2. An apparatus for treating a web of paper including a vacuum chamber, means to permit the web of paper to pass into and out of said vacuum chamber without breaking the vacuum, coating or impregnating means mounted in the vacuum chamber, and

combined drying'drums or cylinders and a liquid bath cooperating to dry the web, the drying drums or cylinders mounted in the liquid and adapted to give a smooth finish to the web as it is dried.`

3. An apparatus for treating material incuding a vacuum chamber, means to permit the material to pass into and out of said vacuum chamber without breaking the vacuum, coating or impregnating means mounted in the vacuum chamber, and drying means including `a heated bath and means mounted in the bath to exert a predetermined degree of tension upon the fibers of the material 'to give the particular finish, smoothness or flatness desired, said bath having no ainity fol or deleterious effect upon said material, and means to permit the dry coated or impregnated material to pass from the vacuum chamber without breakingthe vacuum.

4. An apparatus for treating paper including a vacuum chamber,.means to permit the paper to pass into and out of said vacuumchamber without breaking' the vacuum, coating or impregnating means mounted in the vacuum chamber, and drying means including a heated bath and means mounted in the bath to exert a' predetermined degree of tension upon the fibers of the paper to give the particular finish., smoothness or fiatness desired, said bath havinguo 'afiinity for or deleterious eii'eet upon said paper, and means to permit the dry coated or impregnated paper to pass from the vacuum chamber without breaking the vacuum.

5. An apparatus for treating material including a vacuum chamber, means to permit the material to pass into and out of said vacuum chamber without breaking the vacuum, coating or impreguatng means mounted in the vacuum chamber, and dryin means including a heated bath and rolls o the required diameter mounted in the bath to exert a predetermined' degree of tension upon the fibers of the material to five the partieular finish, smoothness or i'atness desired, said bath having no afiinity for or deleteri- OGDEN MIN TON.

Aous ei'eet upon said material, and means to 20 

